TRIGGERS: Pi-0, Single-cluster and Cosmic 

  = In case of trigger problems, power hits or if reloading is needed,
    CONTACT: Paul Kingsberry, TC16, Room 95, 269-5023
             PAGER: 584-5775

  - For trigger logic, see

      www.jlab.org/primex/subsystems/electronics/,

         Itaru Nakagawa's Diagrams of the HYCAL trigger & associated logic:  

            MLU Bit Assignments 

              (note: MLU3A bit 2 out is our preferred trigger -
                     any 2 hits anywhere, i.e. any MLU3A input)

            Horizontal/Vertical Trigger Strip Groups;

            HYCAL Trigger Groups.

  
  - Logic Summary: 

          HYCAL dynode signals -> summers (UVA120A) -> "groups" 

       -> summer/discriminators (UVA125A) - > "strips" 

          or discriminator (Phillips 7106) for single glass groups

       -> 3 Memory Look-up Units (CAMAC Caen C542), 2 sections each - 

            outputs controlled by 1 set of 6 programs loaded via LabView.

  - MLU CAMAC slot allocations:
 
       MLU1 (horizontal strips and separated glass groups): CAMAC slot 18

       MLU2 (vertical strips and separated glass groups):   CAMAC slot 20

       MLU3 (master):                                       CAMAC slot 22
  
  
  -> 4 triggers selectable without reprogramming/reloading

      (4 different Master MLU3 bits -> Trigger Supervisor):

 MLU3B0  Single-cluster;

 MLU3B1  Cosmics;

         2 PI-0 TRIGGERS (2 clusters) -
         ---------------

   MLU3A2  1) ANY 2 strips/glass-groups firing in any MLU section,
              -----
               adjacent or non-adjacent (minimum bias);


   MLU3A0  2) ANY 2 GLASS strips/groups firing in either MLU (horiz/vert), 
              -----------
               adjacent glass-tungstate strips firing,

               NON-ADJACENT TUNGSTATE strips firing, either MLU,

               or adjacent pairs both horizontally & vertically. 

           [A 3rd pi-0 trigger is also currently available from MLU3A1
            but is seriously flawed both in its design acceptance
            and its implementation in the integrated program. Due to the 
            requirements of the development and increased acceptance of 
            triggers 1 & 2 with limited MLU inputs, optimal implement-
            ation of Trigger #3 (within the limits of its design 
            acceptance) would require the loading of other, archived 
            MLU programs.

   MLU3A1  3) NON-ADJACENT strips/glass-groups firing, glass and W,
              ------------
               or adjacent pairs both horizontally & vertically (W)]